Mud fever in ponies: prevention and treatment

If you keep a pony in the UK, you will encounter mud. And where there is mud, there is mud fever — the bane of every winter. It is not life-threatening, but it is painful, stubborn, and can cause lameness if left untreated. The good news is that most cases are preventable with the right management, and treatable with a consistent routine. Here is a practical guide for UK pony owners facing the mud season.

What is mud fever?

Mud fever (also called pastern dermatitis, scratches, or mud rash) is a bacterial skin infection of the lower legs. It is caused by the bacterium Dermatophilus congolensis and other bacteria that live on the skin. In wet, muddy conditions, the skin softens and cracks, allowing bacteria to enter and establish an infection.

The condition affects the back of the pastern (the area between the fetlock and the hoof), particularly in the heel and fetlock creases. It is most common in winter and early spring when fields are wet and muddy.

Which ponies are most at risk?

• Ponies on wet, poorly drained grazing — heavy clay soil, poached gateways and muddy fields are the primary risk factor.
• Ponies with white legs and thin skin — they are more susceptible than dark-legged ponies, though any pony can be affected.
• Feathered breeds (Dales, Fell, Highland, cob types) — the long hair traps moisture and mud against the skin, creating an ideal environment for bacteria. Paradoxically, feathering can both protect and predispose.
• Ponies in deep mud — the longer the legs are wet and muddy, the higher the risk.

The signs

• Matted hair on the back of the pastern, often with scabs stuck in the hair.
• Small scabs or crusts — these may be hidden under mud and only visible when the leg is cleaned and dried.
• Red, inflamed skin underneath the scabs.
• Oozing or discharge — in more severe cases, a yellowish discharge may seep from infected areas.
• Swelling of the lower leg — a sign the infection is spreading and needs veterinary attention.
• Lameness — the pony may be uncomfortable or lame on the affected leg. This indicates a more serious case.
• Heat in the affected area compared to the rest of the leg.

Prevention: keeping the legs dry

Prevention is far easier than treatment. The principle is simple: keep the skin dry and intact.

Field management

• Improve drainage — rotate gateways, use hardcore or woodchip at gateways and high-traffic areas, and fence off the worst mud patches.
• Limit turnout in extreme wet — on the worst days, consider keeping the pony in for part of the day. This is a judgement call — turnout is important for physical and mental health, but 24/7 in a swamp is not ideal.
• Provide a dry standing area — a hardcore pad, concrete yard or well-bedded stable where the pony can stand out of the mud for part of the day.
• Rotate fields — resting a field allows it to dry and recover.

Leg care

• Do not wash muddy legs with water — this is the most common mistake. Hosing muddy legs keeps the skin wet, which is exactly what bacteria need. Instead, let the mud dry and brush it off with a stiff brush once dry.
• Dry legs thoroughly after turnout — use a clean towel or stable rubber. If you must wash, dry immediately and completely.
• Apply a barrier cream before turnout — petroleum jelly, zinc oxide cream, or specific mud-fever barrier products create a waterproof layer. Reapply after cleaning.
• Keep feathers trimmed — if your pony has heavy feathers, clipping the back of the pasterns (a "hogged heel" or "V-clipping") reduces moisture trapping. Do not clip the whole feather if showing — just the problem area.
• Check legs daily — early detection means easy treatment. Run your hand down the back of each pastern every evening.

Treatment: a consistent routine

If mud fever develops, treatment requires patience and consistency. The goal is to remove the scabs, kill the bacteria, and keep the skin dry.

1. Clip the hair around the affected area so you can see and treat the skin properly.
2. Soften the scabs — apply a warm, wet compress or soak the leg with a dilute antiseptic solution (hibiscrub at 1:100 dilution) for 10 minutes. This softens scabs so they come off gently.
3. Remove scabs gently — do not pick aggressively. Softened scabs should lift off with gentle pressure. Forcing them off causes bleeding and spreads infection. Some scabs may need several days of softening before they come away.
4. Dry the leg completely — use a clean towel, then a hair dryer on a cool setting if needed. The leg must be bone-dry before applying any treatment.
5. Apply a treatment cream — your vet or pharmacy can recommend an appropriate cream. Common options include silver-based creams, antibiotic creams (if prescribed), or specific mud-fever products. Apply to the cleaned, dried skin.
6. Keep the pony off wet ground — box rest on a clean, dry bed, or turnout only on dry, well-drained ground. This is essential — treating mud fever while the pony stands in mud is futile.
7. Repeat daily until the skin has healed and no new scabs are forming. This may take 1–3 weeks.

When to call the vet

Most mild cases respond to the routine above within a week or two. Call your vet if:

• The pony is lame — this suggests the infection has gone deeper.
• The leg is swollen beyond the immediate area — cellulitis (spreading skin infection) can develop and needs antibiotics.
• There is significant discharge or a foul smell — this may indicate a deeper infection.
• The condition is not improving after 7–10 days of consistent treatment.
• The pony has multiple legs affected and is systemically unwell.

Your vet may prescribe oral antibiotics, antibiotic creams, or in severe cases, anti-inflammatories. See our guide on when to call the vet for more guidance.

Mud fever vs other conditions

Not every scabby leg is mud fever. Other conditions that can look similar:

• Photosensitisation — a reaction that causes scabs on pink-skinned (white) legs in sunny weather, not mud. Caused by certain plants in the diet.
• Autoimmune skin conditions — rare but possible; require veterinary diagnosis.
• Chorioptic mange — a mite infestation of the feathered legs, causing itching and scabs. Treated with specific anti-mite products, not mud-fever treatments.
• Fungal infections — similar appearance but requiring anti-fungal treatment.

If the condition is not responding to standard mud-fever treatment, ask your vet to investigate further.

Next steps

• Prepare for winter before it arrives — review your field drainage and stable setup. Read our seasonal care calendar for month-by-month guidance.
• Keep barrier cream and a stiff brush in your first-aid kit.
• Understand the full cost of winter care — see what a first pony really costs.

Keep the legs dry, check them daily, and act at the first sign of a scab. Mud fever is a winter nuisance, not a disaster — but only if you stay on top of it.